State of Hawaii
Seasonal Precipitation Summary

The passage of Tropical Depression Cosme 225 miles south of Hilo on July 20 - 21 brought much needed rain to leeward Kohala sections of the Big Island, as well as the eastern and southeastern slopes. Despite the reprieve from Cosme, drought conditions prevailed across many leeward areas of the state through July, with mandatory water restrictions remaining in place across Up-country Maui, the South Kohala and Hamakua districts on the Big Island, and Waimanalo on Oahu. The approach of Hurricane Flossie on August 14-15 caused concern to the state of Hawaii, however the storm turned west and quickly weakened to a tropical depression before passing south of the Big Island. North- and east-facing slopes managed to catch 1-2 inches of rain from Flossie’s outer shower bands as the hurricane approached the Big Island, while the storm later dropped 1 to 3 inches over windward Maui and 2 to 4 inches over the Koolau Range on Oahu. No significant wind- or flood-related damages were reported, although heavy surf caused minor coastal inundation problems on the Big Island. Trade winds brought frequent showers to windward slopes of the state during September. The boost in trade wind rainfall has helped improve water supply conditions over portions of the state, especially in the Upcountry Maui area which depends on water sent from the windward slopes of Haleakala through a series of ditches. Residents and farmers in Upcountry Maui have been under a mandatory 10 percent cutback in water use since June 13. Drought conditions also continued over east Oahu where a mandatory 30 percent reduction in water use has been in place since September 6 for farms utilizing the Waimanalo Irrigation System.

Additional individual rainfall station information and specific island information for Hawaii can be found in the Monthly Precipitation Summaries.

Hawaii Rainfall Summary for Select Stations, 3rd Quarter 2007

“La Nina conditions are present across the tropical Pacific... Current atmospheric conditions and observed oceanic trends indicate that La Nina conditions will further develop and possibly strengthen during the next 3 months. Based on current conditions... and from historical studies on the effects of cold episodes, wetter [and warmer] than normal conditions are expected over Hawaii and some U.S.-Affiliated Islands during the winter.”